The evidence is imperfect, but if she did put her signature on Old Glory, it would be a clear violation of the Flag Code. Subsection 8, part (g) reads: “The flag should never have placed upon it, nor on any part of it, nor attached to it any mark, insignia, letter, word, figure, design, picture, or drawing of any nature.”

The photo here captures Palin signing the flag at 1:37 in, and visible writing on the flag, which appears at 1:41 in the below video.